Solar Freaks

For anyone interested in playing around with there own MPPT, and understands embedded C code, here is the basic tracking algorithm the Black Magic uses.

Code: Select all

uint8_t SearchAndDestroy(void)
{
   uint32_t newpower = voltage * current;

   if(newpower > oldpower && direction == UP)
   {
      incrementREF();   
      oldpower = newpower;
      return 0;
   }

   if(newpower > oldpower && direction == DOWN)
   {
      decrementREF();
      oldpower = newpower;
      return 0;
   }   

   if(newpower < oldpower && direction == UP)
   {
      decrementREF();
      direction = DOWN;
      oldpower = newpower;
      return 0;
   }

   if(newpower < oldpower && direction == DOWN)
   {
      incrementREF();
      direction = UP;
      oldpower = newpower;
      return 0;
   }

   if(newpower == oldpower)
   {
      incrementREF();
      oldpower = newpower;
      return 0;
   }

   return 0;
}

The tracking routine is executed 10 times a second. Every increment/decrement step shifts the reference up or down 0.2 of a volt.
Ill upload schematics in the next few days.

For those interested in the schematic:



As you can see there is voltage divider on the output going to ADC, thus i can implement output voltage limiting or a battery charging algorithm etc.

The circuit isn't too complex at all, only 50 or so components.
The Easymax has the exact same circuit minus the current sensing.